In times past, advancement within the faculty was the
result of the wizards higher on the ladder dying.
Some of the more ambitious wizards found that helping
matters along was more expedient than waiting
for Death to visit on a more natural time table.
This was the rule until more recently when Mustrum
Ridcully took the position of Archchancellor.
Discovering that Ridcully was annoyingly difficult to
kill, his juniors have settled in for the long wait.